High‐protein vs. standard‐protein diets in overweight and obese patients with heart failure and diabetes mellitus: findings of the Pro‐HEART trial

AIMS: The intermediate‐term effects of dietary protein on cardiometabolic risk factors in overweight and obese patients with heart failure and diabetes mellitus are unknown. We compared the effect of two calorie‐restricted diets on cardiometabolic risk factors in this population. METHODS AND RESULTS: In this randomized controlled study, 76 overweight and obese (mean weight, 107.8 ± 20.8 kg) patients aged 57.7 ± 9.7 years, 72.4% male, were randomized to a high‐protein (30% protein, 40% carbohydrates, and 30% fat) or standard‐protein diet (15% protein, 55% carbohydrates, and 30% fat) for 3 months. Reductions in weight and cardiometabolic risks were evaluated at 3 months. Both diets were equally effective in reducing weight (3.6 vs. 2.9 kg) and waist circumference (1.9 vs. 1.3 cm), but the high‐protein diet decreased to a greater extent glycosylated haemoglobin levels (0.7% vs. 0.1%, P = 0.002), cholesterol (16.8 vs. 0.9 mg/dL, P = 0.031), and triglyceride (25.7 vs. 5.7 mg/dL, P = 0.032), when compared with the standard‐protein diet. The high‐protein diet also significantly improved both systolic and diastolic blood pressure than the standard‐protein diet (P < 0.001 and P = 0.040, respectively). CONCLUSIONS: Both energy‐restricted diets reduced weight and visceral fat. However, the high‐protein diet resulted in greater reductions in cardiometabolic risks relative to a standard‐protein diet. These results suggest that a high‐protein diet may be more effective in reducing cardiometabolic risk in this population, but further trials of longer duration are needed.